Xanthelasma (Xanthoma): the buildup of fats under the surface of the skin, giving the appearance of a raised sore or bump. Xanthomas are most common in older people, and in those with high levels of blood lipids. Xanthelasma vary in size and usually occur on the elbows, joints, knees, hands, feet, or buttocks, although they can develop anywhere in the body. Xanthomas may be a sign of a disease process that leads to increased lipid levels in the body, such as some cancers, diabetes, hyperlipidemia, primary biliary cirrhosis, and familial hypercholesterolemia.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.